Medical breakthrough: Discovery of seven subtypes of medulloblastoma paves the way for more targeted cancer treatment

Tanvi Ambulkar, 27 Sep 2017

Medulloblastoma is a common brain tumour manifesting in children, which can often be life-threatening if not treated promptly and aggressively

Medulloblastoma, a malignant tumour derived from brain cells, is one of the most common brain neoplasms afflicting children. Approximately 70 – 80 children in the United Kingdom are affected each year with medulloblastoma. The current treatment for medulloblastoma could have long-lasting effects on children – and irreversibly affecting their development.

Dylan, a child diagnosed with medulloblastoma at the age of two, has been left with permanent disabilities, resulting from cancer treatment. Initial chemotherapy treatment resulted in relapse of the cancer, and therefore several rounds of radiotherapy and chemotherapy had to be provided, which resulted in damage to the spinal cord and brain.

Jessica Mitchell, Dylan’s mother, comments on the need for less harmful treatment. “If there was a treatment out there that would have saved his life but also his quality of life – I would've been all over that at the time,” she expressed. Dylan had been diagnosed with tumours in the brain and spinal cord as a result of presenting to the Emergency Department with vomiting, screaming and a rash.

As parents have their children’s best interests at heart, they are unwilling to consider death as a possible consequence – and therefore, resort to intensive treatment. Mitchell expressed that she was given a similar choice by the doctors caring for Dylan. “We were given an option to let him go home and die. That wasn't an option for us. So, we opted to treat – but we had to treat very aggressively,” she explained.

Dylan (left) was diagnosed with medulloblastoma when he was only two. He’s seen here with his mother, Jessica Mitchell. Photo credit: The Brain Tumour Charity.

Seven different types of medulloblastoma affecting children

A recent study conducted by the Newcastle University and Northumbria University in conjunction has revealed that paediatric medulloblastoma can be classified into seven categories. The study, published in TheLancet Oncology, points out that each of these classifications has distinct clinical and biological hallmarks, which enable their identification.

Knowledge of these classifications is essential in order to tailor treatment for individual patients. A personalised medicine trial, initiated by the Sydney Children’s Hospital, aims to enrol over 400 children with ongoing potentially invasive cancers. These children will have the opportunity to undergo new treatment which is expected to be life-saving. The primary aim of this trial is to increase the childhood survival rate for cancer to 100%, which represents a 20% increase from the current survival rate of 80%.

Targeted treatment reduces likelihood of long-term effects

The general regimen for cancer treatment currently includes excision of the tumour, radiotherapy or chemotherapy. Radiotherapy and chemotherapy could have potentially damaging systemic effects, which can last for a lifetime. The new treatments being developed are anticipated to have fewer adverse effects – as they only target the tumour subtype in question.

While the personalised medicine trial has started in Sydney; over the next few months, other cities are expected to be involved, as well. This trial holds great promise, especially for those children who have cancers with poor prognoses. Professor Michelle Haber, the lead researcher, comments that, “This is a programme for the kids who have little chance of surviving their cancer.” A previous trial revealed that children receiving standard treatment only have a survival rate of approximately 30%.

Lasting disabilities from current cancer treatment

It is estimated that medulloblastoma is responsible for approximately 10% of all childhood cancer mortality, which represents a considerable proportion of deaths due to this cancer. Understanding the way tumours respond to treatment could facilitate design of drugs that are more specific and less systemic in their effects. It may also reduce the need for interventional surgery, which has associated risks such as vascular complications and infection.

Cliff O’Gorman, chief executive of Children with Cancer in the UK highlights the importance of investing in research of this kind. “It is crucial that we invest in clinical trials to build on findings like this and make cutting-edge treatment and precision medicine a reality for all young cancer patients in the UK,” he expressed.

This research is especially beneficial for children, as lifelong disabilities could significantly impair quality of life. Current courses of treatment can also stunt potential growth and impact social behaviour. More targeted, specific treatment tailored to the biological nature of each tumour is essential to reduce the complications resulting from standard treatment. MIMS

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